Java Code Examples for com.bigdata.rdf.model.BigdataStatement#getSubject()

/**
 * @see {@link Templates#REMOVE_REIFIED_ELEMENT}
 */
String removeReifiedElement(final BlazeReifiedElement e) {
    final BigdataBNode sid = e.rdfId();
    final BigdataStatement stmt = sid.getStatement();
    final Resource s = stmt.getSubject();
    final URI p = stmt.getPredicate();
    final Value o = stmt.getObject();
    final StringBuilder vc = buildValuesClause(new StringBuilder(), 
            new String[] { "?s", "?p", "?o" }, 
            new Value[]  { s, p, o });
    final String queryStr =
            REMOVE_REIFIED_ELEMENT.replace(Templates.VALUES, vc.toString());
    return queryStr;
}
 

/**
     * Insert or remove a statement.
     * 
     * @param conn
     *            The connection on which to write the mutation.
     * @param spo
     *            The statement.
     * @param insert
     *            <code>true</code> iff the statement is to be inserted and
     *            <code>false</code> iff the statement is to be removed.
     * @throws SailException
     */
    private static void addOrRemoveStatement(final BigdataSailConnection conn,
            final BigdataStatement spo, final boolean insert) throws SailException {

        final Resource s = (Resource) spo.getSubject();

        final URI p = (URI) spo.getPredicate();
        
        final Value o = (Value) spo.getObject();
        
        /*
         * If [c] is not bound, then using an empty Resource[] for the contexts.
         * 
         * On insert, this will cause the data to be added to the null graph.
         * 
         * On remove, this will cause the statements to be removed from all
         * contexts (on remove it is interpreted as a wildcard).
         */
        
        final Resource c = (Resource) (spo.getContext() == null ? null : spo
                .getContext());
        
        final Resource[] contexts = (Resource[]) (c == null ? NO_CONTEXTS
                : new Resource[] { c });
        
        if(log.isTraceEnabled())
            log.trace((insert ? "INSERT" : "DELETE") + ": <" + s + "," + p
                    + "," + o + "," + Arrays.toString(contexts));
        
        if (insert) {
        
            conn.addStatement(s, p, o, contexts);
            
        } else {

//            /*
//             * We need to handle blank nodes (which can appear in the subject or
//             * object position) as unbound variables.
//             */
//            
//            final Resource s1 = s instanceof BNode ? null : s;
//
//            final Value o1 = o instanceof BNode ? null : o;
//            
//            conn.removeStatements(s1, p, o1, contexts);

            /**
             * 
             * @see <a
             *      href="https://sourceforge.net/apps/trac/bigdata/ticket/571">
             *      DELETE/INSERT WHERE handling of blank nodes </a>
             */
            conn.removeStatements(s, p, o, contexts);

        }

    }
 

/**
     * Insert or remove a statement (INSERT DATA or DELETE DATA).
     * 
     * @param conn
     *            The connection on which to write the mutation.
     * @param spo
     *            The statement.
     * @param insert
     *            <code>true</code> iff the statement is to be inserted and
     *            <code>false</code> iff the statement is to be removed.
     * @throws SailException
     */
    private static void addOrRemoveStatementData(final BigdataSailConnection conn,
            final BigdataStatement stmt, final boolean insert) throws SailException {

//        final Resource s = (Resource) spo.s().getValue();
//
//        final URI p = (URI) spo.p().getValue();
//        
//        final Value o = (Value) spo.o().getValue();

        final Resource s = stmt.getSubject();
        
        final URI p = stmt.getPredicate();
        
        final Value o = stmt.getObject();
        
        /*
         * If [c] is not bound, then using an empty Resource[] for the contexts.
         * 
         * On insert, this will cause the data to be added to the null graph.
         * 
         * On remove, this will cause the statements to be removed from all
         * contexts (on remove it is interpreted as a wildcard).
         */
        
        final Resource c = (Resource) (stmt.getContext() == null ? null : stmt
                .getContext());

        final Resource[] contexts = (Resource[]) (c == null ? NO_CONTEXTS
                : new Resource[] { c });
        
        if(log.isTraceEnabled())
            log.trace((insert ? "INSERT" : "DELETE") + ": <" + s + "," + p
                    + "," + o + "," + Arrays.toString(contexts));
        
        if (insert) {
        
            conn.addStatement(s, p, o, contexts);
            
        } else {
         
            conn.removeStatements(s, p, o, contexts);
            
        }

    }
 

/**
 * TODO In order to support CBD, we will also have to recognize
 * statements that describe blank nodes that are part of the description
 * of a described resource as belonging to that described resource. This
 * is necessary in order to capture the transitive closure of the
 * resource description specified by CBD. The code in this method only
 * recognizes statements that directly have a described resource as a
 * subject or object. We probably need a reverse map that will allow us
 * to navigate from a BigdataValue (or perhaps just a BigdataBNode) to
 * all described resources for which that value was observed. That map
 * might only need to contain the blank nodes since the description can
 * never expand beyond a statement having a blank node in the subject
 * (or object) position and a non-blank node in the object (or subject)
 * position.
 * 
 * @see <a href="https://sourceforge.net/apps/trac/bigdata/ticket/578">
 *      Concise Bounded Description </a>
 */
@Override
public BigdataStatement next() throws QueryEvaluationException {

    // A statement produced by the CONSTRUCT iterator.
    final BigdataStatement stmt = src.next();

    // Check the Subject.
    {
        
        final BigdataValue s = stmt.getSubject();

        // Is the subject one of the described resources?
        if (describedResources.contains(s)) {

            record(s, stmt);

        }
        
    }

    // Check the Object.
    {
        final BigdataValue o = stmt.getObject();

        // Is the object one of the described resources?
        if (describedResources.contains(o)) {

            record(o, stmt);

        }
        
    }
    
    return stmt;

}
 

private void checkSid(final BigdataBNode sid, final URI p, final Value o) {
 	
 	final BigdataStatement stmt = sid.getStatement();
 	
 	if ((p == RDF_SUBJECT && stmt.getSubject() != o) ||
 			(p == RDF_PREDICATE && stmt.getPredicate() != o) ||
 				(p == RDF_OBJECT && stmt.getObject() != o)) {
 		
throw new UnificationException("sid cannot refer to multiple statements");
 		
 	}
 	
 }